A smart-technology wearable wristband may be able to automatically detect cardiac arrest, according to new research published today in Circulation: Arrhythmia and Electrophysiology, a peer-reviewed scientific journal of the American Heart Association. The DETECT‑1b study analyzed data from 49 adults in the Netherlands with abnormal heart rhythms who underwent a medical procedure in which a life-threatening heart rhythm was briefly induced. The algorithm-based wristband detected cardiac arrest 92% of the time, offering hope for faster medical assistance and increased survival odds when cardiac arrest occurs outside of a hospital.
“Our findings are important because many out-of-hospital cardiac arrests are unwitnessed. A smart technology wristband capable of automatically detecting cardiac arrest and triggering an alert could function as a digital witness,” said study senior author Judith Bonnes, M.D., Ph.D., a cardiologist at the Radboud University Medical Center in Nijmegen, Netherlands. “With the device automatically notifying emergency services or nearby trained responders, help could arrive sooner, which may significantly improve survival chances.”
The study examined whether a medically certified smart technology wristband that continuously monitors vital signs can detect when the heart suddenly stops pumping blood. The device uses a light-based technique (photoplethysmography algorithm) to measure changes in blood flow in the wrist. During the procedure, pulseless ventricular tachycardia (pVT) or ventricular fibrillation (VF) was induced. The wristband detected cardiac arrest accurately in 92% of cases: 100% of ventricular fibrillation and 90% of pulseless ventricular tachycardia. Nine events were classified as false positives during 125 hours of recording. In the per-patient analysis, accuracy for detecting the irregular rhythms was 92%.
“This is the first study to externally validate such an algorithm using patient data, which is an important step toward developing a reliable detection system for real-world use,” said lead study author Roos Edgar, M.Sc., a technical physician at Radboud University Medical Center. Many commercially available smart watches use similar sensors; however, most are not designed to detect cardiac arrest.
In a future application, the algorithm could be used to alert nearby lay rescuers, emergency services, or both. “The goal is to connect the wristband to emergency dispatch centers and volunteer responder networks in the Netherlands so that nearby rescuers and ambulance services can be alerted immediately when cardiac arrest is detected,” Bonnes said.
Cameron Dezfulian, M.D., FAHA, chair of the American Heart Association’s Resuscitation Science Symposium Program Committee, who was not involved in the study, noted the low frequency of false positives as impressive. “This study parallels findings from a study in Canada and one in the U.S. that shows this technology has great potential,” he said. However, he added that pulseless electrical activity, the most common presenting rhythm in all cardiac arrest, accounts for a small number of validation data for such wearable sensors, indicating the need for further research.
The research was conducted in a controlled clinical setting, which is a limitation. The system’s effectiveness and reliability in real-world conditions still need to be evaluated in future studies. The DETECT-1b study involved 49 adults wearing the smart technology wristband while undergoing ventricular tachycardia ablation or subcutaneous implantable cardioverter defibrillator implantation. Participants had a median age of 66 years, and 41 (84%) were men. The research is part of the broader DETECT project, a collaboration of several hospitals and a company in the Netherlands.
